In performing various dental procedures, dental professionals routinely apply various liquid materials to preparation sites on the teeth, gums and/or other areas of the mouth of a patient. Such materials include primers, adhesives and other liquid dental preparations.
To the degree possible, storage, preparation and use of these materials should be carried out in an environment and manner consistent with good infection control practices. Thus, the manner of packaging and storing liquid dental materials should accommodate the need to dispense the dental material by such a process, including the equipment and devices for dispensing, and to maintain an appropriate level of sterility of the material over time, especially when multiple doses of material are stored in bulk. Typically, this means that the reusable devices and products are disinfected with cold sterilants between uses. Certain applying equipment or devices are usually sterilized in an autoclave between uses.
Additionally, in some cases, dental liquids need to be stored in a way to limit the permeation of solvents from the dental liquid through its container. For example, most dental adhesive systems today contain solvents to increase their wettability so that they are easier to apply to a tooth surface. During storage, however, it is important to prevent substantial evaporation of the solvent from the liquid material in order to protect the effectiveness of the liquid material. A vessel made of material having a limited permeability to solvents can be used, such as made from relatively thick plastic, or a foil pouch can be provided about the stored quantity of material. Sealable plastic containers having presealable caps or other closures are common from which multiple doses can be dispensed. Foil pouches typically contain single doses either directly therein, or within a unit dose container sealed therein.
An advantage of a resealable container having multiple doses is that it would typically require less storage space as compared to single dose packages. Single dose packages, such as contained within foil pouches, require substantially greater space than the volume of liquid dental material contained within each package.
There exist a number of different devices and methods for storing and applying such liquid dental materials. One common procedure for storing and applying liquid dental materials involves dispensing the dental material from a sealable bulk vial into a well which can be either reusable or disposable. The sealable vial maintains sufficient sterility and avoids excessive evaporation of solvents. Once the liquid material is placed into the well, a brush or other fiber tipped applicator is dipped into the well so that the fiber tip of the applicator can retain a quantity of the liquid material. The material is then coated onto the tooth surface or other preparation site. Often, additional coats of the material are required and so the applicator will be re-dipped into the well so that additional coats can be applied. If the material is light cured, such as for example those materials commercially available under the trade designation "3M Single Bond Dental Adhesive System" from Minnesota Mining & Manufacturing Company of St. Paul, Minn., care must be taken to shield the well from light exposure during this procedure. After the procedure, the fiber tip of the applicator and the well, if disposable, are disposed of. Typically, the entire brush or the brush handle; the well, if non-disposable; and the bulk vials are disinfected with a liquid disinfectant.
A number of brush types are known for use as dental applicators and can be used with the above procedure. A relatively standard type brush is simply a small paint brush comprising bristles fixed with an elongate handle. Another type of brush includes relatively small fibers adhered to and extending radially from a spherical tip portion of an elongate brush handle. Such a brush is known as a flocked tip brush comprising nonabsorbent fibers between which liquid can be held in suspension, an example of which is commercially available under the trade designation "Microbrush" from Microbrush Corporation of Clearwater, Fla. Yet another type of brush comprises a reusable brush handle connected with a replaceable brush tip. The tip may be a standard bristle type brush or a flocked tip. A replaceable flocked tip brush is described in copending U.S. design patent application Ser. No. 29/070,517 and in U.S. design Pat. No. 377,216 to Mark. This type of brush allows disposal of the brush tip and sterilization and re-use of the handle.
Regardless of the type of brush used with the above described procedure, however, the procedure has a number of drawbacks. First, spillage is possible either in filling the well from the bulk vial or in applying the material to the preparation site. Second, the lid or cap of the bulk vial must be handled which can cause contamination, requires two hands and can be difficult with gloves on. Third, two hands are also required for both filling the well and applying the liquid. Fourth, because the material must first be dispensed from a bulk source into the well before application, the procedure can be relatively time consuming. Fifth, if the well is not disposable, the well must be cleaned and the well, brush, applicator handle and bulk vial all must be disinfected. Thus, cleanup can also be time consuming. Sixth, if the bulk vial is opaque, it can be difficult to determine how many applications of the liquid material are left before additional material must be supplied. Finally, gloves make all parts of the procedure which require handling or manipulation of items difficult. Gloves are typically worn during dental procedures for infection control.
Another system for storage, dispensing, and applying liquid dental material delivers the material via a bulk syringe source having multiple doses of material. A bulk quantity of liquid dental material is provided in a re-usable syringe and dispensed through its hollow dispensing tip. This approach allows for direct application of the material to a tooth without the need to use a disposable or reusable dispensing well. However, the entire syringe must be disinfected after each use. Also, if the bulk syringe source is opaque, it can be difficult to determine how many applications of the liquid material remain. Care must also be taken to effectively reseal the syringe after each use to maintain the material's effectiveness.
A third type of system for applying liquid dental material uses unit dose packaging. This type of system uses a disposable package containing approximately enough liquid dental material for a single application. An example is the delivery system commercially available under the trade designation "Optibond Solo" from Kerr Company of Orange, Calif. A small plastic container having dental material therein is provided within a foil pouch. This process requires opening the sealed foil pouch and subsequently breaking a unit dose plastic container to access the liquid dental material. Then, a brush or other fiber tipped applicator can be used as above to apply the material to a preparation site. This eliminates the need for using a well and dispensing the material into the well.
Because the package is sealed, there is no need for a separate, sealable bulk vial for infection control and to prevent excessive evaporation of solvents. Also, this system avoids clean-up requirements of a separate bulk vial and well. However, the system still requires two hands and spillage can occur if the package is set down on a dental tray or in transfer of the material from the package to the preparation site with the applicator. Additionally, opening the packages can be difficult while wearing gloves. Further, as above, storage of the separate unit dose packages can take up a relatively large amount of space.